Santiago Romero wrote: > >> Hi, >> >> Quoting the documentation[1]: >> >> "The unverified_recipient_defer_code parameter (default 450) specifies >> the numerical Postfix SMTP server reply code when a recipient address >> probe fails with some temporary error. Some sites insist on changing >> this into 250. NOTE: This change turns MX servers into backscatter >> sources when the load is high." >> >> > > So, do you mean that changing this parameter to 250 would make postfix > to accept the email? >
Hi, No. You should leave this parameter in its default value. I realize now that I shouldn't have quoted the entire piece from the documentation, only the relevant part. You're not the only one who misinterpreted my post. Sorry for that. I only wanted to quote this: "The unverified_recipient_defer_code parameter (default 450) specifies the numerical Postfix SMTP server reply code when a recipient address probe fails with some temporary error." This is the relevant part, and answers the question you had. Everything else is irrelevant - and as Brian Evans ponted out earlier (and the documentation too), setting this parameter to 250 will generate bounces and backscatter. And that is very bad! Using "reject_unverified_recipient" should produce the behaviour you are asking for. I also set "unverified_recipient_reject_code = 550". This makes postfix permanently reject when the recipient address is confirmed not existing. When postfix does not know it'll reject the connection with a 450 (or whatever unverified_recipient_defer_code is set to), which should be fine for most cases. When the address is confirmed to exist, everything is cool and mail is accepted. Maybe I should add that I use Postfix v2.6.2 just in case there are differences in default values between versions. HTH, Mikael